17. Roper Lair
If the player characters enter from the chamber from the East, read:

As the downward slope opens into a chamber, a wide, natural pillar blocks the path, creating a T-intersection. The North path reveals a tunnel on that side of the chamber. The South path has a lower ceiling, but gradually inclines as it curves North.

If the player characters enter from the North:

You follow the trail of claw marks to the next chamber in the South. A wide, natural pillar blocks your view of the Western side of the chamber.

When the characters finally enter the chamber proper:

Within the large chamber, along the Southwestern wall is a large stalagmite with what appears to be vine-like vegetation around it.

The roper is using its tentacles as a lure, baiting plant eaters and the curious alike into examining this strange, and lone, feature in the chamber. The roper attacks when a creature gets within 15 feet, or if any creature in range ignores it and turns to leave.

Corpse. Behind the roper’s position is the corpse of a male svirfneblin, or deep gnome. It is torn in half, and long dead by at least a day. It would have been half the size of a human, and is bald with stone-colored skin. It takes a DC 20 INT (History) check to recognize it as more than just “almost like a halfling”.

Treasure. The corpse holds 15 gp. If you wish, you can switch this with 15 pieces of earth quartz, what the people of the Underdark uses instead of gold coins in this world. It also has an unrefined pale yellow spell crystal (DC 15 Intelligence (Arcana) to identify), and a map to his home in the Crystal Caverns.

18. Claw Marks
Cut into the stone here are two sets of four jagged lines. A DC 15 Wisdom (Perception) check reveals something stuck in the jagged lines: a bloody piece of fingernail. It is clear that the tracks begin to the North and end as they enter the chamber to the South.